Targeting cell cycle kinases and kinesins in anticancer drug development

The cell cycle is regulated by kinases such as the cyclin-dependent kinases (CDKs) and non-CDKs, which include Aurora and polo-like kinases, as well as checkpoint proteins. Mitotic kinesins are involved in the establishment of the mitotic spindle formation and function, and also play a role in cell cycle control. The disruption of the cell cycle is a hallmark of malignancy. Genetic or epigenetic events result in the upregulation of these kinases and mitotic kinesins in a myriad of tumour types, suggesting that their inhibition could result in preferential targeting of malignant cells. Such findings make the development of these inhibitors a rational and attractive new area for cancer therapeutics. Although challenges of potency and non-specificity have hampered their progress through the clinic, several novel compounds are presently in various phases of clinical trial evaluation.

Targeting Aurora kinases in ovarian cancer

Although recurrent epithelial ovarian cancer initially responds well to current first-line adjuvant therapy, eventually the disease becomes resistant to chemotherapy. Novel strategies are needed to reverse chemoresistance in order to treat relapsed ovarian cancer effectively. One strategy is to target aberrant expression activation of Aurora kinases that are essential for the regulation of chromosome segregation and cytokinesis during mitosis and which play a role in tumourigenesis and progression in a wide range of human tumours, including ovarian cancer. The purpose of this article is to review Aurora kinases and their inhibitors in human epithelial ovarian cancer as an impetus to the development of effective and less toxic regimens for ovarian cancer. In addition, this review tries to define the differences between cytotoxic chemotherapeutic agents and molecular therapeutic agents: both groups of agents have either a single specific target or multiple specific targets, while their differences lie in their toxicity profiles and the way to determine their dosages for further studies. The authors propose that Aurora kinase inhibitors be developed as molecular therapeutic agents in order to minimise their toxicities and maximise their antitumour activities for ovarian cancer treatment.